Add integration tests for coordinator-mode TypeScript tasks

[guan404ming]

Related Issue

closes #69290

Why

Coordinator-mode TypeScript tasks had no Airflow-level end-to-end coverage and ts-sdk changes triggered no integration tests in CI

How

• Add a ts_sdk e2e test mode mirroring the Go SDK's: build the ts-sdk example bundle with pnpm in an ephemeral Node container, deploy it with its stub Dag, and assert Dag success, Python <-> TS XCom round-trips, Connection/Variable reads, and coordinator logs reaching the task-log store
• Provide the worker's Node.js runtime via a node-provider compose service in docker/ts.yml
• Wire CI through a new TS_SDK_E2E_FILES selective-checks group -> run-ts-sdk-e2e-tests -> a dedicated e2e job, with doc and test updates

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• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst, in airflow-core/newsfragments. You can add this file in a follow-up commit after the PR is created so you know the PR number.